Help!! Overheating

Hello there fanatics, i got an E46 323ci and the problem is that whenever i leave my car on and idle for a few minutes the temperature meter starts going up. Here's the weird part, the car does not over heat there is enough coolant and the fan turns on. After leaving the car idle and the meter telling me that its overheating the car does not shut off. To bring the needle down to normal, i just need to drive and the needle will go back to normal.

need help! i dont know if its the fan or sensors.

Since you just got it I would do a complete cooling system overhaul excluding the radiator.

But most likely the thermostat is the issue or air in the system.

Fan.

EDIT: Nvm, you said fan turns on.

Thermostat maybe not opening all the way. When you drive, the water pump gets turned faster and the increased flow cools it back down.

You'll know it's the fan if it isn't turning on while idling. Try turning on the A/C

It's most likely the thermostat or water pump. Old plastic hoses don't like new plastic connectors so I hope you're ready to bust out the wallet!

Read Mango's cooling sticky above...read 3-5 other long threads with 'overheating' in the thread title (advanced search)...and make sure you read until you puke.

Do not drive when overheating at all...at all! You're risking your engine in case you didn't know.

sounds like the thermostat, but as "solidjalke" suggested i would do a complete cooling system over haul. Starting with the water pump, thermostat, both upper and lower hoses and fresh coolant BMW coolant mixed 50/50 with distilled water. Drain you block to and make sure you bleed the air out properly when you refill the radiator.

Thanks you guys.
I just bought a whole new cooling system for it. It worked fine at first, so my first move is to make sure that all the air is out completely. If that's not the case then it must be the thermostat, unless the condenser has anything to do with it.

If you replaced the cooling system, why do you think it must be therm...unless you used an aftermarket, aluminum housing therm...reputedly not good at all.

But, bleeding gives many an issue here. See my 'alternative bleeding' method in Mango's sticky...and you can sort things out pretty quickly if it's just that. Make sure you have your heat on.

I'll go over and take a look at it.

I dont have an aluminium thermo, altho i was thinking of going for it. Are you suggesting to stay with the plastic?

Most will agree with sticking with the OEM thermostat (Behr or Wahler) I had 3 Autozone thermostats fail on me so I'm sticking with OEM on the thermostat

The OEM ones are plastic housing

Originally Posted by 323ciSub-0

I'll go over and take a look at it.

I dont have an aluminium thermo, altho i was thinking of going for it. Are you suggesting to stay with the plastic?

Yes. There is no reason to go with the aluminum housing. The plastic ones don't break. The thermostat inside them may, but the housing is adequate. Get a Wahler brand thermostat. The aluminum ones tend to come with shitty thermostats or wrong thermostats and your car will run at the wrong temp. They also don't tend to have the connection for the heating element that allows the car's computer to open the thermostat earlier if you're driving hard.

Thanks
I appreciate it.